The present invention relates generally to patient support structures. More particularly, the present invention deals with a patient support couch or table assembly adapted to be used with a diagnostic imaging apparatus.
More specifically, the present invention relates to a patient positioning couch associated with a CT scanner. However, it should be appreciated by those skilled in the art that the couch can also be utilized with various other types of medical diagnostic apparatuses such as magnetic resonance imaging apparatus or X-ray apparatus.
Computerized tomography (CT) apparatus is well known. The CT scanner is quite popular as a tool for diagnosis of tumors and the like. Owing to good quality tomographic images with low dosage X-ray radiation, the CT scanner has become well accepted by the medical profession. CT scanners have a circular opening in which an X-ray beam and an opposing scintillator-type detector are translated and rotated according to well known procedures.
In order to obtain tomographic images of a patient with a CT scanner or X-ray CT apparatus, it is necessary that the patient be located exactly at a predetermined position inside the opening of a scan gantry of the apparatus. For this reason, such apparatus has been provided with a patient handling couch which is moveable vertically to be in line with the scan gantry, and horizontally in and out of the scan gantry. Several couches are known for this purpose. However, various difficulties have been experienced with the known couches. Among these are the fact that dirt, dust and liquids can accumulate in the rail mechanism on which the couch moves in and out of the scan gantry. Another problem is that there is a considerable amount of rolling resistance experienced by the conventional rollers which allow movement of the couch in and out of the scan gantry. Sometimes the couch also experiences binding.
For those couches which do provide a scissors type mechanism for the elevation of the couch and its subframe from a base, the conventional scissors assemblies are not stable, rigid and able to accurately elevate the couch and its subframe to a desired height. The known conventional scissors mechanisms, while they are advantageous in the abstract, suffer in practice also from torque as well as deflection problems and are not provided with as stable and as solid a support base as would be desirable.
Accordingly, it has been considered desirable to develop a new and improved patient support couch or table apparatus which would overcome the above-referenced problems and others and provide a new and improved table construction.